Visual detection method and device for defects of liquid crystal display screen

Abstract

The invention relates to a visual detection method and device for defects of a liquid crystal display screen. The method comprises the following steps: adjusting positions of buttons of button disks of a matrix electromagnetic switch according to the arrangement situation of keys of a sample to be detected, so as to enable the positions of the buttons to be fit with the arrangement of the keys of the sample to be detected; collecting a template image of each button in an off-line manner; collecting the image of the liquid crystal display screen in real time by using a CCD (charge coupled device) and a lens which are connected with an embedded processor; catching one frame of an image to be detected, and performing four steps of preprocessing operation of color image graying, binaryzation, median filtering and positioning by a projection method on the image; performing template matching calculation on the preprocessed image and the template images by a sliding template matching method, obtaining a visual detection result of the defects, and performing character recognition on the result without defects. The invention also provides a corresponding system device. The method provided by the invention has the advantages of high speed and high accuracy, overcomes the defects of low manual defect detection efficiency of the liquid crystal display screen, high cost and poor consistency, and meanwhile, realizes integration of detection and recognition.

Description

technical field [0001] The invention belongs to the technical field of machine vision image measurement and automatic control, and in particular relates to a liquid crystal screen defect visual detection method and device. technical background [0002] In recent years, with the rapid development of image processing and pattern recognition technology, the degree of intelligence and automation of industrial production is gradually deepening. Although the field of production automation is quite extensive, for the defect detection of products, the existing inspection machines can only detect the appearance features such as scratches, spots, and pits on the product surface. For instruments with LCD screens such as multimeters, it is impossible to detect and mark visual defects while identifying the information displayed on the screen. Therefore, the factory inspection of such products still can only rely on manual inspection. This detection method not only increases the inspecti...

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Problems solved by technology

[0003] In order to overcome the above-mentioned shortcomings of manual detection of liquid crystal screen defects, the purpose of the present invention is to provide a method and device for visual detection of liquid crystal screen defects, to realize automatic identification and automatic detection of information displayed on the liquid crystal screen, and to locate and mark defective positions

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